Skip to main content

Full text of "The Cambridge Natural History"

See other formats

4/2           THE   BROWN   RAT   AND   THE   BLACK   RAT          CHAP.
frequents barns, and is thus sometimes mistaken for the Common
Mouse, from which, however, it is to be distinguished by its
coloration and longer ears. The latter, M. musculus, is too
familiar to need much description. A curious variety of it has
occurred. This has a thickened and a folded skin like that of
a Rhinoceros, and the hair has disappeared. The Black Hat,
M. rattus> is like a large Mouse, and is. smaller and blacker in
colour than the " Hanoverian Bat." It is sometimes called the
" Old English Hat," but seems nevertheless to be not a truly
indigenous Hodent. It has been so defeated by competition with
the Hanoverian Hat that It is now not a common species in this
The Hanoverian or Brown Hat, M. decuinanus, is a larger and
a browner animal than the last. It is very widely distributed
through the globe, no doubt largely on account of the fact
that it is readily transported by man. The same is the case
with the Common Mouse, whose real origin must be a matter of
doubt. The original home of the Brown Rat is thought by
Dr. Blanford to be Mongolia. There is so far a justification
for the name " Hanoverian Hat" that the animal seems to
have reached this country about the year 17*28. But there
is no reason for calling it, as is sometimes done, the Norway
Some members of this genus, whose fur is interspersed with
spines, or which are quite spiny, have been separated as a genus,
Leggada,, which, however, is not generally allowed.
Closely allied again is Chiruromys,. which has a strongly
prehensile tail, a feature which is not common among the
Myomorpha, though Dendromys, a tree-frequenting form, and
3fw5 minwtus, already spoken of, show the same character.
Many Mice seem to have prehensile tails, which they can curl
round branches; but it is not so fully developed as an the species
just named.
A number of other genera are referable to the true Mice, the
sub-family Murinae of Thomas's classification. The Syrian and
African Acornys has very spiny fur, so much so that "when
it has its spines erected it is almost indistinguishable at
the first glance from a diminutive hedgehog." The genera
Crteetoinya, Mcdacomys, Lophwromys, SaecostomuA, Da&ymys are
restricted to the Ethiopian region. JVesolcia is Oriental, reaching